Gun-sighting device



Jan. 29, 1952 R BURLEY 2,583,815

GUN-SIGHTING DEVICE Filed Aug 8, 1940 .INVENTOR 60561 i MBurle %MJ/ f ATTORNEY Patented Jan. 29, 1952 UNITED STATES PATENT OFFlCE GUN-SIGHTIN G DEVICE Application August 8, 1940, Serial No. 351,819

This invention relates to sighting devices and in particular to gun-sights intended for use with fiexibly' mounted guns, such as anti-aircraft weapons.

To successfully fire upon an objective, such as an aircraft, which is moving at a relatively high velocity with respect to the gun, it is necessary that the gunner have some mechanical means for obtaining a correct solution to the problems involving motion of the target, so that the gun may be trained to some advance position with respect to the target in order to effect a hit. Many approaches to this problem have been attempted, but none, prior to the present invention, have attained the success necessary for a dependable defensive weapon.

It is an object of the present invention to provide a computer as an accessory to a standard anti-aircraft gun-mount that will be accurate and efiicient in operation.

It is an additional object to provide a gunsight which permits the training of a gun upon a target in accordance with the velocity of the target, and also in accordance with the elevation, the range and change of range thereof.

Other objects include the provision of a novel gun-sight employing mechanical means under the control of a plurality of observers to direct a gun in order to efiect a hit, and also to provide a sighting device which will translate to a suitable gun-mount, the necessary angular motions to direct a gun-barrel sufficiently in advance of the moving target to effect a hit.

Other objects will become apparent from a study of the following specification when made in conjunction with the attached drawing which shows, in a single figure, a perspective of the gun-sight of the present invention with certain parts broken away for a better understanding thereof.

The gun sight which is the subject of the present'inventionis intended and is suitable for use with an anti-aircraft gun and is operable over the normal ranges of modern anti-aircraft guns to direct fire upon "target aircraft in an unrestricted arc in train and over the normal angles of depression in elevation for which antiaircraft guns are suited. The novel gun sight may be'used, of course, with shipboard as well as land batteries of guns.

- The gun-sight is designated generally at 0, and includes a telescope H, which is connected by suitable means, such-as arms l2, to the housing l3 containing certain elements of v the gunsight. Housing l3 'iscarried by bracket member Claims. (Cl. 33 -49) M upon a horizontally rotatable turntable l5 having gear teeth It on its periphery. Rotation of housing 13 about the vertical axis of turntable l5 givesthe housing motio n in train. Housing 13 is also rotatable in elevation about pivot points [1, only one of which is shown. A gyroscope l8 of any conventional type having a gimbal ring'*'l 9 through which passes the horizontal spin axle 20 is mounted within housing l3. At right angles to the spin axis, gyroscope i8 is provided with horizontal trunnions 2! extending from gimbal I9, forming an axis of precession for gyroscope I8. Depending normally vertically from gimbal I9 is an integral arm 22 having at its outer end a horizontally extending pin 23 which engages with a slotted crank arm 24 pivoted upon a crank-shaft 25, which also carries a crank-arm 26, to which is pivotally connected in any conventional manner, a link 21. This link is pivoted at its other end to a crank-arm 28, towhich is attached a crank-shaft 29 supported by any suitable bearing members, not shown. At the end of crank-shaft 29, opposite crank-arm 28, there is mounted a mirror member 30 for rotation about crank-shaft 29 as an axis.

A second gyroscope 3| is mounted in gimb'al 32 to spin about a vertical axle 33. Gimbal 32 has an integral arm 34'norm'ally extending horizontally which carries at its outer end, a'pin member 35 engageable with the slotted crankarm 36. Trunnions 31 extend horizontally through gimbal 32 and form a horizontal axis of precession for gyroscope '3I. Crank arm 36 is pivoted about a shaft 38 which is gearedto a shaft 39 by means of mitre gears 40, and shaft 39 forms a horizontal axis about which mirror member 4| is rotatable. Gimbal '32 carries a fixed block 42 towhich is attached by rivets or other suitable means, one end'of a leaf-spring 43. A similar leaf-spring 44 is attached to gimbal IS in the manner'above described; 4

A range control mechanism, includingga transversely extending rod 45, having a bearing member '46, and a journal bearing member 41, is operatively connected to a shaft '48 tojwhich is attached handle member 49 by'means of meshing gear segments 56'. Intermediate the ends of rod 45 there is secured a barrel cam 5|, having-a cam track 52 therein, which will be described later. A block 53, which is apertured to receive barrel cam 51, carries a pin'member 54 which engages with cam track 52. 'Pairs of laterally projecting pins 55 and 5G 's'lidably engage leaf; springs 44 and 43,-respe'ctively,"and blocl; memf ber 53 is 'prevented from rotating'about rod 45,

and is constrained to move parallel to leafsprings 43 and 44 by means of guide rods 5'! and 58 passing therethrough and supported by any conventional means, not shown.

Housing I3 also contains a light source, such as lamp 59, a plate 60 of ground glass, or other suitable material, carrying a reticule member 6| engraved, or otherwise fixed thereon, and any suitable lens member or means 62 for focusing an image of the reticule so that an operator may observe it, as will be later described. Housing I3 is provided with a window 63 adjacent which, on the outside of housing I3, there is carried a tubular sighting element, such as a collimating telescope 64 having a plate carrying cross-hairs 65. Trunnions 66 extend from opposite sides of telescope 64 and are fixed to a yoke 61 which is rotatable about a shaft 68, the latter being supported by bracket 69 attached to housing I3 by any suitable means. Yoke 61 also carries a depending bracket 10 to whichis affixed an electric motor II which may be a synchronous transmitter of the electric repeating system, commonly known as an Autosyn or Selsyn. The lower one of trunnions 66 extends beneath yoke 61 and terminates in a gear member I2, which meshes with another gear 13 carried by the rotor of motor 1 I.

Shaft 68 terminates in a beveled gear 74, which is part of a differential mechanism 15 composed of idler beveled gears I6 and I1, and a fourth beveled gear 18, all meshing in a manner which is conventional with a simple differential of this type. Bevel gear 18 is fixed to one end of shaft I20, and suitably supported by any conventional bearing member, not shown, and the other end of shaft I20 carries a pinion I2I which engages with mating teeth formed on the gear quadrant I22 integral with bracket I4. Rotation of housing I3 in elevation about pivot points I! will cause rotation of shaft I20 and consequently rotation of bevel gear 80, since in operation of the gun sight, shaft 68 :cannot rotate freely. The ring gear I9 meshes with a beveled gear80 fixed to one end of a shaft 8|, while there is attached a pulley'82 to the other end'of shaft 8I. Motion is transmitted from shaft IN to a parallel shaft 83 having ,a pulley 84 at one end, driven by pulley 82 through a belt .85. The other end of shaft 89 carries a pulley 86 which is connected to the rotor 67 of an Autosyn transmitting motor 88 through a belt 89. Shaft 83 is supported intermediate its ends by a bearing member 90 which is aflixed to housing I3 by means of a bracket 9I. Intermediate the ends of shaft 83, there is mounted a worm-gear 92 which meshes with a gear wheel 93 carried by a shaft 94 and is keyed thereto by means of a spline member 95. Shaft 94 also carries a knob member 96 at one end and a block member 91 at its other end, in which it is freely journaled for rotation with respect to block member 91. An upstandingrod member 98, which terminates between two spaced collar members 99, is attached to rod 45 by a loose connection, such as a V-bend in the top end of rod 98. Shaft 94 also carries a cam member I90 which is composed of a plurality of different cam surfaces, the purpose of which will be described later.

Segmental plate member I M is fixed to one end of transversely extending rod 45 and has a slot I02 cut therein, whichslot freely receives a pin member I03 connected to a guiding block I04. Slot I02 has a curvature which is predetermined and which acts to move a toothed plate member I05 in accordance with the target range introduced by an operator of handle 49. The teeth on plate member I05 mesh with a ear I58 which is connected to Autosyn motor 88 by means of a tubular hollow sha'ft member I01, which is connected to the stator member of Autosyn motor 88, and which serves to rotate the stator member upon vertical motion of plate I05. Plate I05 (which is biased to move downwardly by any conventional means such as a spring member, not shown) is slidable under the control of an operator of handle 49 along the cam follower I08 having one end pivoted at I09 to bracket 9|, and its other end resting upon a selected cam surface of cam I00. Plate I05 is restricted to move along the cam follower I08 by means of pin members IIO carried by bracket III, which is rigidly attached to housing I3 and to the casing of Autosyn motor 38. Pins III] are freely slidable within guiding block I04 which supports the plate I05.

Teeth I 5 of turntable I5 are in mesh with teeth of pinion II2, which is carried by the rotor of an Autosyn transmitting motor I #3. Bymeans of electrical leads H5, H6 and Ill, transmitting motors II, 88 and H3 are in circuit with receiving motors, not shown, embodied in gun-mount II4. Thus, motion of housing I3, as modified by motion in elevation of telescope 64, is transmitted to a synchronous repeater within gunmount II4 to control the elevation of a conventional gun, not shown, through any desirable servo-system. Rotation of housing I3 in train is transmitted to a synchronous repeater in gunmount H4 in order to rotate the gun in train in accordance with rotation of housing I3. Further, motion of telescope 64 in traverse is transmitted through lead II! from motor II to a synchronous repeater, in gun-mount I I4 in order to direct a gun in traverse by the amount of motion in traverse introduced by the operator of telescope 64.

The proper amount of gun-barrel lead is introduced and controls the gun-barrel through the operation of an observer who moves telescope 64 in order to keep the apparent image of reticule 60 always upon the cross-hairs 65 of the telescope. In so doing, the operator transmits elevational and traverse corrections to gunmount I I4 to cause the gun-barrel to lead the target by the amounts in elevation and traverse that are correct for the obtaining of a hit.

The droop of a trajectory of a projectile will vary with the range of the target, and means are shown whereby correction for the droop, depending upon the elevation and the range of a target, is readily obtained. The cam surfaces of cam I00 are formed so that upon motion of housing I3 in elevation, toothed plate I05 will cause rotation of gear Hi5 and the stator of Autosyn 88 to modify the elevational motion transmitted to gun-mount I I4. The elevational motion is modifled in accordance with range, since the position of plate I05 along cam follower I08 depends upon the range correction inserted by the operator of handle 49. The elevational motion is also modified in accordance with the elevation of the target, since upon rotation of collimating telescope 94 in elevation, the outer end of cam follower I08 will ride up or down upon one of cam surfaces on cam I00 to put in the appropriate correction for droop, depending upon the elevation of collimating telescope. The correction for droop is also dependent upon the rate of change of the range of the target, and this correction modifies the angular motion transmitted to gun-mount II4 throughAutosyn 88, since the operator of knob 96 can select any one of the three (or more, if desired) cam surfaces. No attempt has been made herein to show the particular form of cam surfaces applicable to afford a correction for range rate, 'but an operator can determine, by experience, which of the available cam surfaces to be used forv particular firing conditions. This correction for super-elevation is worked into the electrical circuit of Autosyn 88 by rotating the stator portion of Autosyn 08 by different amounts, depending upon, not only the rangeof a target, but also different arbitrary rates of range change. The operator who has observed the range of a target will insert the proper correction for range by manipulation of handle 49, and the same or another operatorcan select the proper cam surface'to compensate for difi'erent rates of range change. This latter correction m'ade particularly where the percentage change of range, over relatively short intervals, is of considerable amount.

The correction for range rate, or rate of range change, is effected by longitudinal movement of knob 96, causing transverse rod 45 to advance or retard barrel cam block 53, and pin members 55 and 56 as a unit, along leaf-springs 43 and 44. This changes the rate of precession of gyroscopes I8. and 3|, and consequently eifects movement of mirrors 30 and Min such a degree asto direct fire upon a target when the range of the target has been changed appreciably over the In the operation of the gun-sight to aim a gun at a moving target, an observer sights the target through telescope II and maintains it trained upon the target. The. motion required to maintaintelescope II upon the target causes gyroscopes I0 and 3| to precess. It is well known that the force of precession of a gyroscope is proportional to the velocity at which its axis is angularlydisplaced. It is known, too, that if the precessive force is opposed by a spring such as leaf springs 43 and 44, then therate at which the gyroscope precesses upon suffering a displacing torque is proportional to the angular rate of displacement of the gyroscopic axis. The axes of mirrors 30 and 4| are connected through linkages above described, to arms 22 and 34, respectively, which rotate about the precessive axes of the gyroscopes I8 and 3|, respectively. j Hence the rate at which these mirrors rotate is proportional to the rate of precession of the controlled gyroscopes, and the image of reticule 0| in the line of light of telescope 64, will be displaced due to the movement of either or both of mirrors 30 and 4|. A second operator will keep the crosshairs 65 of telescope 64 trained upon the reticule image, and this training attion causes the proper lead angle of the gun in elevation and traverse to be obtained. Since leaf-springs 43 and 44 vary the rate of precession of gyroscopes I8 and 3| in accordance with the range of the target, a third operator is utilized to make range findings and place the proper range correction in the device of the present invention bymanipulation of handle 40,- which may coact, of course with: a calibrated scale, not shown. The curvatures of cam track 52 and of slot I02 are such that range readings from a standard range finding device can be utilized to adjust the rate of precession of gyroscopes I8 and 3|, as well as the travel ,of plate I05 along cam follower I08 by simply rotating handle 49 to the proper calibrated position on a scale, not shown. The correction for change of range may be made by the range finding operator, or by a fourth operator, who directly observes and estimates the rate at which the target is changing its range. He can, therefore, move knob 96 in or out to insert the proper oper-- ating cam, and also to set the proper length of leaf-springs 43 and 44 that will control the precession of gyroscopes I8 and 3| in the amount necessary to direct a projectile upon the moving target.

b When knob 36 is advanced or retarded to place any one of the different surfaces of cam I00 in operation with cam follower I08, it will beevi-z dent that rod 45, moving transversely of housing |3, under the action of upstanding rod member 98, will cause plate member IN to slide along pin member I03, either toward or away from plate member I05, carrying also the top of gear segments 50. For this reason, the lower of gear segments 50 is made sufficiently wide that movement of rod 45 will not interfere with the meshing of gear segments 50.

It should be borne in mind that the gun-sight shown in perspective in the drawing is meant to be principally a schematic showing, and not an actual assembly of a complete gun-sight. For this reason, no attempt has been made to show the gear and pulley members in their true ratios, and it should be borne in mind that in the construction of an actual gun-sight, in accordance with the invention, it is intended that all meshing gears and all interacting pulleys. be arranged in the proper relation to transmit true angular motion to gun-mount I I4 representative of the angular motions of gun-sight I0.

While only one embodiment of the present invention has been shown in the drawing, it is to be understood that various changes may be made without departing from the scope of the present invention. For this reason, it is intended not to limit the invention by the description herein given as an example, but solely by the scope of the appended claims.

What is claimed is:

1. A gun-sighting device including a telescope, a turntable rotatable in train upon rotation of said telescope, a housing, rigid connecting means between said telescope and said housing, means for pivotally mounting said housing so that the latter is rotatable in train with said turntable and rotatable in elevation with respect to said turntable, said housing containing a source of light therein, a reticule adjacent said source of light, a first mirror pivotally mounted, gyroscopic means for controlling the rotation of said first mirror, a second mirror pivotally mounted at right angles to said first mirror, second gyroscopic means for controlling the rotation of said second mirror, said source of light being positioned to cast light through said reticule upon said mirrors insequence, one of said gyroscopic means being mounted to precess upon rotation of said housing in train and the other of said gyroscopic means being mounted to precess upon-rotation of said housing in elevation, a tubular sighting element outside of said housing and havingan eyepiece 1 and cross-hairs defining a line of 'sight, and means for pivotally mounting said tubular sighting element within the field of light reflected from said mirrors in sequence for rotation in elevation and train with respect to said housing.

2. A gun-sight including an optical targetsighting device, a housing rotatable in train and elevation, but fixed with respect to said optical target-sighting device, said housing having therein a first gyroscope mounted to precess upon movement of said housing in train, a first mirror rotatably mounted and under the control of said first gyroscope, a second gyroscope mounted to precess upon movement of said housing in elevation, a second mirror rotatab1y mounted'and controlled by said second gyroscope, areticule, a light source for casting light through said reticule upon said mirrors in series, and a sighting element having an eyepiece and cross-hairs mounted for. viewing said reticule and being rotatable in elevation and train with respect to said housing.

3. A gun-sight comprising a housing mounted for rotation in elevation and train, a target-sighting device fixed with respect to said housing, means within said housing for anticipating a position of a target in train, including a gyroscope having an axis of precession, a mirror rotatably mounted for movement by said gyroscope upon precession about said axis, a second sighting device carried by said housing but rotatable in elevation and in train independently of said housingmeans within said housing for anticipating the position of atarget in elevation, including a second gyroscope having an axis of precession, a mirror rotatably mounted under the control of said second gyroscope to rotate upon motion of said gyroscope to cause precessionabout said axis, a light source within said housing, and a reticule adjacent thereof, said reticule, mirrors and second sighting device being located in sequence in the line of light from said source.

4. A gun-sight comprising a telescope, a housing on which said telescope is mounted and movable upon motion of the latter, a first gyroscope mounted Within said housing for precession upon movement of said housing in elevation, a second gyroscope mounted withinsaid housin 'for precession upon movement of said housing in train, mirrors rotatably mounted within said housin and at least one under the control of each gyroscope, a reticule, a light source for casting light through said reticule upon said mirrors in series. and a sighting element havin an exterior eyepiece rotatably mounted on said housing, said mirrors being rotatable upon precession of said gyroscopes to displace an image of said reticule in the eyepiece of said sighting element. 5. A gun-sight comprising a target-sighting device mounted for rotation in elevation and train, a housing rotatable therewith for related movement in elevation and train, 'gyroscopic means mounted within said houisng for precession upon movement of said housing in elevation and train, rotatable mirror means carried by said housing and mounted so as to be rotated upon precession of said gyr'oscopic means, a light source, a reticule adjacent said light source, and a sighting member rotatably mounted on said housing in such a manner as to be positioned within the field of light reflected from said mirror means and passing through said reticule. W j

6. A gun-sight for sighting upon a moving targetycomprising a reticule, a light source for casting light through said reticule to form an image thereof; a first gyroscope mounted for pre-- tated in response to precession of said first gyroscope for reflecting and moving the image of said reticule in elevation, a second gyroscope mounted for precession upon movement of said sight in train, a second'rotatable mirror mounted to be rotated in response to precession of said second gyroscope for reflecting and moving the image of said reticule in train, means dependent upon the range of the target for varying the amount of precession of said gyroscopes, a sighting element for sighting and collimating the image of said reticule and mounted for movement in elevation and train with respect to said sight, and electrical means controlled "by movements of said sighting element for repeating the angular movements of said sight in elevation and train, whereby the gun with which said-sight is adapted to be associated may be moved correspondingl in elevation and train. i

7. Agun-sight comprisingv atarget-sighting device mounted for rotation in elevation and train,

a first gyroscope mounted for precession in 'response'to movement of said target-sighting device in elevation, a second gyroscope mounted for precession in response to movement of said target-sighting devicein train, a reticule, a light source for casting light through said reticule to form an image thereof, a sighting member movable in elevation'and train independently of said target-sighting device, and mirror means disposed in the line of the light from said source and between said reticule and saidsighting member, said mirror means being movable in response to precession of said gyroscopes.

8. A gun-sight including a target-sighting device mounted for rotation in elevation and train, a sighting member rotatably mounted on said target-sighting device and also rotatable independently thereof in elevation and train, gyroscopic means mounted for precession in response to movement of said target-sighting devicein elevation and train, a reticule, a light source for casting light through said reticule to form an image thereof, mirror elements in the line of light between said reticule and said sighting member capable of relative angular motion and controlled by the precession of said gyroscopic means for moving the image of said reticule in elevation and train, and means for modifying the motion of precession of said gyroscopic means in accordance with the range of the target.

9. A gun-sight comprising a target-sighting element rotatable in elevation and train, a housing rotatable therewith, a second sighting device rotatable with said housing in train, but also being independently rotatable in elevation and train, a reticule, means operable 'upon rotation of said housing to cause an image of said reticule to move within the field of view of said second sighting device, and motion repeating means connected to and operated by said second sighting device so that, as thelatter is moved to keep the image of said reticule within its field of view, said means will sense the angular movement of said second sighting device.

'10. A gun-sight comprising a telescope, a housing on which said telescope is mounted and movable upon motionof the latter in elevation and train,.a first gyroscope mounted. within said housing for precession upon movement of said housing in elevation, a second gyroscope mounted within said housing for precession in response to movement of said housing in train, a plurality of mirrors rotatably mounted in said housing and controlled by said gyroscopes, a reticule in said housing, a light source for casting light through said reticule upon said mirrors in series to form an image of said reticule, and a sighting member having an eyepiece carried b and rotatably mounted on said housing, said mirrors being rotatable upon precession of said gyroscopes to displace the image of said reticule in the eyepiece of said sighting member.

ROBERT M. BURLEY.

REFERENCES CITED The following references are of record in the file of this patent:

Number 10 Number 10 UNITED STATES PATENTS v Name Date Kaminski June 10, 1924 Kaminski July 1, 1924 Willard Nov. 21, 1933 Talafre et a1 Nov. 13, 1934 Fieux Feb. 1, 1938 FOREIGN PATENTS Country Date Great Britain Mar. 8, 1912 Great Britain Feb. 18, 1938 Great Britain Jan. 9, 1939 France Apr. 7, 1921 

